On Wed, May 08, 2013 at 06:31:48PM +0200, Arnd Bergmann wrote:

On Wednesday 08 May 2013, Greg KH wrote:

quoted

quoted

just mention there is not hardware reason to not use the generic ttySx
in place of ttyAS as we have only one IP that handle serial on this
family of SoC

personally I'll switch to ttySx

Great, then you can use the same major/minor range as well, so there's
no more objection from me about this :)

Does that work these days when you have kernel with multiple built-in
uart drivers?

It "should", as the major/minor registration should only happen when the
hardware is found, but I haven't tested it out, so I can't say for sure.

I think it would be good if all uarts were using the same name space
and major/minor numbers, but I think the mess we currently have is
the result of the tty_register_driver() interface reserving the
device number range at driver load time, independent of the presence
of devices.  I would assume that normal distro kernels always ship
with an 8250 driver built-in to allow using that as the console,
and if I read the code correctly, that currently prevents another
uart driver from registering the same major/minor numbers.

We can always fix this if needed :)

thanks,

greg k-h